1. Asia-Pacific Centre for Animal Health, Faculty of Veterinary Science, The University of Melbourne, Parkville, Victoria 3010, Australia
2. Institute of Bacteriology, Mycology and Hygiene, University of Veterinary Medicine, Vienna, A-1210 Vienna, Austria
3. INRA, ENVT, UMR 1225, 31076 Toulouse, France
4. Microbiology Department, Basic Medical College, Guiyang Medical University, Guiyang, Guizhou 550004, PR China
5. Center of Excellence for Vaccine Research, Department of Pathobiology and Veterinary Science, The University of Connecticut, Storrs, Connecticut 06269, USA